1. Field of the Invention
The invention is directed to an electronic control panel testing apparatus which electronically simulates the operations of an off-highway vehicle. A technician inputs electronic signals from the apparatus into a control panel for a vehicle, visually monitors the results, and compares the results with the projected results for a correct control panel.
2. Description of the Prior Art
Many of the functions and operations of large off-highway vehicles are controlled eletronically by circuitry mounted on replaceable panels (boards or cards). As such, when the vehicle appears to be malfunctioning, the operator must determine if something is wrong with the electrical or mechanical system of the vehicle.
Previously, for a technician to determine if a control panel was operating correctly, various power supplies, meters an associated wiring would be gathered on board the vehicle having the potentially defective panel. The electrical signals necessary to manipulate the control panel would result from operating the truck and manipulating the testing equipment appropriately.
In the prior method of testing the control panel the technician and testing equipment was exposed to vibrations, noise, and dangerously high voltage levels (up to 1600 volts) immediately adjacent to the control panel. Furthermore, it was necessary to employ an assistant to operate the vehicle during testing and take the vehicle out of service for testing and repairs on the electronic control panel. Therefore, testing the control panel was a relatively costly procedure.
In addition to the cost involved in testing the panels, it was also difficult to achieve accurate measurements due to the testing conditions. Road conditions such as bumps and potholes result in considerable difficulty both in reading the meters and attempting to make adjustments on the control panels being tested. The hostile environment on board the operating vehicle frequently caused a loss of calibration of the test equipment.
Simulators have been used to test the electrical systems on automotive vehicles, as disclosed in U.S. Pat. Nos. 4,300,205 and 4,339,801. These automotive simulators have been designed for cars having simpler electrical monitoring and control systems and lower voltage inputs than off-highway vehicles control panels. In addition monitoring and recording systems have been mounted on highway trucks to monitor engine parameters that can be later analyzed, as disclosed in U.S. Pat. No. 4,258,421.